Seagrape bonsai care is most successful when they are grown in the full sun. It is a tropical plant, and difficult to keep leaves small in low light conditions. Dioecious seagrapes have male and female plants that grow in close proximity. The flowers are fragrant and ivory-colored.
Coccoloba uvifera can live in both wet and dry conditions, but prefers to be kept evenly moist in containers.
It barely tolerates frosts (it will lose leaves) and does not tolerate freezes. Grapes are often mistakenly believed to be poisonous. They are pale green when they are young and turn a deep purplish red when they are ripe. Because they are a single large seed, there is not much flesh. The taste is a combination of sweet and tart.
Seagrape Bonsai Care and Pests
Coccoloba is susceptible to very few pests and/or diseases.
One common pest does attack new growth. Aphids cause distorted leaves and/or display chewing damage. Catch this problem early.
Spray with a soapy detergent and water mix, a commercial soap based insecticide or a common ‘house & garden’ spray.
There is one more horrific pest — fortunately not common.
The first sign of this pest is frass (looks like sawdust.) Individual wilted leaves are the next indicator.
The borer is located just behind the wilted leaf in the center of the stem. It actually hollows out the stem.
I only had the experience once and used a systemic product by Bayer.
Pruning and Repotting
As warm nights become consistent, heavy pruning to both branches and roots (if necessary) can be done.
Although sea grape bonsai care does not require frequent root pruning, they should be checked annually. It does not mind crowded roots.
A trim, every two years may be enough.
When pruning branches, DO NOT use a concave cutter.
Coccoloba branches have segments that can easily be recognized. (Much like the Ficus variety shown here.)
Cutting into a segment, will cause it to die back to the next ring.
When you cut half way between the ‘rings’ the remaining portion will dry up and eventually fall off. It’s best not to get too close to the leaf you want to keep.
A Smaller Leaf Sea Grape?
There is a much smaller leaf variety, Coccoloba diversifolia (Pigeon Plum.)
The leaves are usually 2-4 inches and have a slightly different shape.
It is less commercially available and has been much ignored as bonsai.
In nature, it is a small upright understory tree, often with multiple trunks.
As tropical nurseries begin to appreciate this species as a landscape plant, we may see it used more often as bonsai.